html, body {
    height: 100%;
    min-height: 100%;
    margin: 0;
    padding: 0;
}
.split-pane-divider {
    background: #aaa;
}
#left-component {
    width: 20em;
}
#my-divider {
    left: 20em; /* Same as left component width */
    width: 5px;
}
#right-component {
    left: 20em;  /* Same as left component width */
    margin-left: 5px;  /* Same as divider width */
}